Since the OED lexicographers are over an office divider from where I am sitting I guess I'm in a good position to answer this.
The most important point to make about modern dictionaries is that they are descriptive not prescriptive. That is to say that they describe the language as it evolves rather than tell you how you should use it. Lexicographers are like scientists though they do not generally consider themselves as such, everything they include in their dictionaries has made it there through painstaking linguistic research.
Please believe me when I tell you that my lexicographer colleagues have no interest in being 'hip'. Trust me on this one, I see them walk past my desk every day. Instead they are passionately interested in language and when a word has amassed enough evidence of usage in modern English they include it in their modern English dictionaries. Evidence of sufficiently common usage to be considered to have entered the language is their only value judgement.
It is also worth spelling out the differences between the different Oxford dictionaries. The OED is a massive multi-volume historical dictionary based on human research. You would use it to find the etymologies of words over a milennium. The Oxford Dictionary of English and the Concise Oxford English Dictionary however are corpus based dictionaries, they are derived from computational analysis of a billion-plus word corpus of contemporary English. That kind of stuff should be right up the average Slashdotter's street. Thus words like 'woot' and 'leet' (The lexicographers are funny about numbers in words, don't blame me) will not have been selected for trendiness but because the corpus analysis tells us people are using them.
The multi-volume book sells rather well as it happens. Not to many individuals but there are a lot of schools, universities and libraries in the world. And yes, we do have two
dictionary websites. But as to a desperate attempt to stay profitable, the OED itself is not likely ever to do that. It took decades to produce its first edition, decades more for the second. We are a publishing company that is also a not-for-profit department of a major university so the OED is a project created for its academic value rather than its monetary return.
